Pneumatic fastener driving tool

ABSTRACT

A pneumatic fastener driving tool adapted for driving fasteners which are automatically fed to the tool through a spring operated feeding magazine attached to the barrel of the tool. The automatic feeding is accomplished by the provision of a clip containing interconnected successively aligned fasteners each of which is encased in a guide washer. The clip includes at one point between each pair of fasteners a shear plane and the tool includes an anvil adapted to support the fastener in the clip next following the fastener to be driven by the tool. The anvil is linked to a safety probe that prevents firing of the tool unless depressed as when engaging a work surface. The linkage functions to move the anvil into engagement with said next succeeding fastener when the safety probe is depressed and when removed from the work surface, the anvil is retracted to permit feeding of the clip and allow the said next succeeding fastener to be moved into the barrel of the tool for driving and aligning the then next succeeding fastener over the anvil.

United States Patent [.191

Pomeroy 1 PNEUMATIC FASTENER DRIVING TOOL [75] Inventor: Raymond Visher Pomeroy, Portland,

Oreg.

[73] Assignee: Omark Industries, Inc., Portland,

Oreg.

22 Filed: Oct. 19, 1973 [21] Appl. N0.Z 407,855

[52] U.S. Cl 227/8, 227/95, 227/130 [51] Int. Cl. B25c 1/04 [58] Field of Search 227/8, 66, 95, 96, 97, 227/98, 136, 130, 109

[56] References Cited UNITED STATES PATENTS 3,027,560 4/1962 Nelson 227/66 3,464,614 9/1969 Volkmann 227/8 3,741,455 6/1973 Wandel et a1... 227/8 3,774,293 11/1973 Golsch 227/66 X Primary Examiner-Granville Y. Custer, Jr.

1 1 .lan.7,1l975 [5 7] ABSTRACT A pneumatic fastener driving'tool adapted for driving fasteners which are automatically fed to the tool through a spring operated feeding magazine attached to the barrel of the tool. The automatic feeding is accomplished by the provision of a clip containing interconnected successively aligned fasteners each of which is encased in a guide washer. The clip includes at one point between each pair of fasteners a shear plane and the tool includes an anvil adapted to support the fastener in the clip next following the fastener to be driven by the tool. The anvil is linked to a safety probe that prevents firing of the tool unless depressed as when engaging a work surface. The linkage functions to move the anvil into engagement with said next succeeding fastener when the safety probe is depressed and when removed from the work surface. the anvil is retracted to permit feeding of the clip and allow the said next succeeding fastener to be moved into the barrel of the tool for driving and aligning the then next succeeding fastener over the anvil.

3 Claims, 9 Drawing Figures PATENTEDJAH 1% 3,858,782

sum 1 or E PNEUMATIC FASTENER DRIVING TOOL HISTORY This invention relates to a pneumatic tool adapted for driving fasteners into hard work surfaces, e.g., concrete and steel, and more particularly to an anvil utilized in the tool for aiding the shearing of the fastener being driven from a unitized clip of fasteners.

Pneumatic tools used for driving fasteners, e.g., staples and nails, are common and extensively used in the construction industry. However, typically such a pneumatic tool is limited to the relatively easy applications such as driving of nails into wood or fastening flooring to wood joists and the like. Also commonly used in the construction industry are powder actuated tools which are used for the more difficult driving tasks where air pressure is not sufficient, such as driving larger shank diameter fasteners into concrete and steel. Such tools are required to incorporate substantial safety features with great care taken to insure that the fasteners are driven straight so as to avoid deflecting the fastener back at the operator. Between these two extremes there is a range of fasteners adapted for applications which can be driven with the power output of air pressure but for which pneumatic. driving tools have not heretofore been available.

It is well recognized that pneumatic tools have many features which are preferred to that of the powder actuated tools. Thus, whereas pneumatic tools are generally adapted for automatic repeat firing, the powder actuated tools require reloading after each fastener is driven. However, the higher power requirements of the intermediate fastener applications create a number of problems in designing which have heretofore been unsolved. It is therefore an object of the present invention to provide a pneumatic tool having the design characteristics which enable the tool to utilize the greater available air pressures for driving the intermediate range of fasteners, e.g., at pressures up to 160 p.s.i. as compared to conventional pneumatic nailers limited generally to 120 p.s.i.

BRIEF DESCRIPTION One of the problems in providing a nailer that will drive powder actuated type fasteners is in the provision of sufficient guide means whereby the fasteners are insured of being driven at an angle normal to the work surface and thereby avoid the hazardous problem of having the fasteners deflected out of the work surface and back towards the operator. The present invention has overcome this problem of prior pneumatic nailer designs by the provision of substantial guide means for the fasteners whereby the fasteners are securely guided through the barrel and into the work surface. The use of substantial guide means has produced its own problem in that in order to utilize the automatic feeding feature of the nailer it is desired that the fasteners be fed to the tool in clip form. It has been found that in attempting to produce a clip with the substantial guide means as contemplated herein, upon feeding the clip into the tool the driver blade engages and tears the leading fastener away from the clip and in doing so ruptures the clip and guide washers of other fasteners. Accordingly, it is a further object of the present invention to provide means whereby the fastener immediately following the fastener being driven is supported on an anvil so that as the driving blade strikes the lead fastener a very precise shearing of the fastener and its washer away from the clip is achieved. Whereas a fixed position of the anvil would interfere with the desired feeding of the successive fasteners, a retraction mechanism is provided whereby the anvil is linked to the safety probe such that as the tool is removed from the work surface, the probe retracts and thereby retracts the anvil to permit the feeding of the clip. These and other features of the invention will be more clearly understood by reference to the following detailed description and drawings wherein:

FIG. 1 is a side view of a pneumatic fastener driving tool in accordance with the present invention showing parts'thereof broken away;

FIG. 2 is an enlarged view of the nose portion of the tool shown in FIG. I as well as a portion of the magazine utilized for guiding the clip of fasteners into the nose piece, both of which are shown in section;

FIG. 2 a is a sectional view taken on section lines 2a 2a of FIG. 2;

FIG. 3 is an enlarged view of a portion of a clip holding two fasteners;

FIG. 4 illustrates the clip with interconnected washer like members but with the fasteners removed;

FIG. 5 is a schematic view illustrating the operation of the fastener driving tool with the driving blade driving a fastener;

FIG. 6 is a view similar to FIG. 5 but showing the fastener having been driven into a work surface and the driving blade retracted;

FIG. 7 is a view similar to FIG. 5 but showing a further fastener in position to be driven and further show ing in phantom lines the anvil and its interconnection with the safety probe; and

FIG. 8 is a view taken on section lines 8-8 of FIG. 2.

Referring to FIG. 1 of the drawings, a fastener driving tool 10 includes a handle portion 12 which further functions as a compressed air reservior which com pressed air is provided to the handle through air line 14. A power head 16 includes various valving mechanism 18 adapted to be actuated by a trigger mechanism 20 for introducing compressed air from the handle 12 to the top of a piston 22. Fixed to the piston 22 is a driver blade 24 which, as will be noted by reference to FIG. 2, is adapted to be driven through a cylinder portion 26 of the power head 16 and through opening 28 into a nose piece 30 to there engage fasteners and drive them into a work surface 32.

Referring again to FIG. I, the fasteners are introduced into the nose piece 30 through a magazine 34 which includes a guide track 36. The guide track 36 guides a clip 38 containing fasteners 58 as shown in FIG. 2a. The clip is urged down the guide track 36 by a pusher mechanism 40 that is actuated by a negator spring 42. The clip 38 is placed on the guide track 36 of the magazine by drawing the finger 44 of the pusher mechanism 40 back until it engages the holder 45. The clip is then inserted through opening 46 and the holder is released. A safety probe 48 slideably attached to the nose piece 30 includes a linkage member 50 which is adapted to engage a lever 52 when the safety probe is retracted as when the nose piece 30 is pushed against the work surface 32. Unless the linkage is engaging the lever, i.e., unless the safety probe is retracted, the trigger 20 cannot function to release the valving 18. This arrangement is common to the industry and further explanation is not deemed necessary. A bracket 49 that slides on the nose piece 30 is secured to the safety probe 48. An anvil 54 is positioned in a seat 55 of the bracket 49 and is secured there by set screws 56 (see FIG. 8).

Referring now to FIGS. 3 and 4, the fasteners 58 are encased in sleeve segments 60 of the clip 38. Washer segments 64 are provided on the lower edge of the sleeve segment 60 and around the pointed end of the fastener 58. A shear lug 66 is carried by the sleeve segment 60 and extends rearwardly to engage and integrally connect to the washer 64 of the following fastener. A rib 68 is designed with a cammed leading top edge 70. The cammed edge 70 functions to prevent the head of the fastener being driven from interferring contact with the guide washer of the following fastener. The various components of the clip elements are shown in FIG. 4 with the fasteners being removed from the clip for purposes of clarity. Thus, it will be seen that the lower edge surface of the clip corresponds to the point of the fastener. Support of the anvil is thus provided to the clip element rather than having the point of the fas tener resting directly on the anvil. It will be noted that the shear plane is established by a notch 74. It will be understood that the material of the clip element including the washer 64 and sleeve segment 60 shatters as the fastener is driven into the work surface and disintegrates leaving only a residue of plastic bits to be swept away from the work surface.

OPERATION Referring to the FIGS. 5, 6 and 7, it will be seen that the tool is illustrated in FIG. with the safety probe 48 being engaged by the work surface 32. The piston 22 has been actuated by the trigger mechanism so that the driver blade has just engaged the leading fastener located in the nose piece. The clip element associated with that fastener has been sheared free of the remainder of the clip and the guide washer 64 is guiding the fastener down the nose piece to insure a straight driving angle.

Referring to FIG. 6, it will be seen that the tool as illustrated has driven a fastener into the work surface 32 with the plastic having been shattered. The driving blade has been returned to its starting position for a repeat firing.

Referring to FIG. 7, it will be seen that the tool has been removed from the work surface thereby allowing the safety probe to be extended below the nose piece, and upon such extension the anvil is retracted (note the arrows). Such retraction of the anvil permits the clip to be advanced by the feeder mechanism of the magazine whereby the next successive fastener is brought into alignment with the nose piece. At this point, the operation is repeated, i.e., the tool is placed against the work surface, the safety probe is retracted to permit tiring, and the anvil is raised into engagement with the next succeeding fastener.

Referring to FIG. 8 of the drawings, the anvil as previously described is fastened to the bracket by set screws 56. The set screws 56 can be loosened to permit the anvil to be removed from the bracket and replaced by either a similar anvil or varying anvils having different lengths. Thus, it will be understood that the tool is adapted to drive different lengths of fasteners merely by exchanging the anvil with one that is shorter or longer, depending upon the desired length of the fastener.

Having thus described the preferred embodiment of the present invention, it will be apparent to those skilled in the art that the inventive features can be modified to accommodate various pneumatic tools. Thus, the invention is not to be limited by the aforementioned specific embodiment but is to encompass tools and clips for use in such tools as defined in the appended claims hereto.

I claim:

1. A pneumatic fastener driving tool comprising; an air pressure source, apower head connected to said air pressure source, a piston in said power head adapted to be driven by compressed air from said air pressure source, valving in the power head for controlling the introduction of the compressed air to the piston, trigger mechanism associated with said valving, a nose piece connected to said power head and including means for receiving a drivable fastener, a driving blade connected to said piston and adapted to be driven through said power head into the nose piece to there engage a fastener for driving the fastener into a work surface, a magazine connected to the nose piece including feed ing mechanism for feeding a clip of fasteners into the nose piece, an anvil carried by the nose piece and aligned with the fastener in the magazine which immediately follows the one contained in the nose piece, said anvil having a supporting surface adapted to support the said following fastener to protect the clip from fracturing as the leading fastener is severed from the clip by the driving blade, and means to move the anvil between a fastener supporting position and a retracted position to permit feeding of the fasteners into the nose piece.

2. A pneumatic fastener driving tool as defined in claim 1 including a safety probe carried by the nose piece for controlling the actuation of the trigger mechanism, the anvil connected to the safety probe and being moveable between a fastener supporting position and a retracted position to permit feeding of the fasteners into the nose piece in response to engagement and disengagement of the safety probe with the work surface.

3. A pneumatic fastener driving tool comprising; an air pressure source, a power head connected to said air pressure source, a piston in said power head adapted to be driven by compressed air from said air pressure source, valving in the power head for controlling the introduction of the compressed air to the piston, trigger mechanism associated with said valving, a nose piece connected to said power head and including means for receiving a drivable fastener, a driving blade connected to said piston and adapted to be driven through said power head into the nose piece to there engage a fastener for driving the fastener into a work surface, a magazine connected to the nose piece including feeding mechanism for feeding fasteners into the nose piece, an anvil carried by the nose piece and aligned with the fastener in the magazine which immediately follows the one contained in the nose piece, a safety probe carried by the nose piece controlling the actuation of the trigger mechanism, a bracket connecting the anvil to the safety probe to move the anvil between a fastener supporting position and a retracted position to permit feeding of the fasteners into the nose piece in response to engagement and disengagement of the safety probe with the work surface, said anvil being removably connected to the bracket whereby the anvil can be interchanged with other anvils to accommodate different lengths of fasteners. 

1. A pneumatic fastener driving tool comprising; an air pressure source, a power head connected to said air pressure source, a piston in said power head adapted to be driven by compressed air from said air pressure source, valving in the power head for controlling the introduction of the compressed air to the piston, trigger mechanism associated with said valving, a nose piece connected to said power head and including means for receiving a drivable fastener, a driving blade connected to said piston and adapted to be driven through said power head into the nose piece to there engage a fastener for driving the fastener into a work surface, a magazine connected to the nose piece including feeding mechanism for feeding a clip of fasteners into the nose piece, an anvil carried by the nose piece and aligned with the fastener in the magazine which immediately follows the one contained in the nose piece, said anvil having a supporting surface adapted to support the said following fastener to protect the clip from fracturing as the leading fastener is severed from the clip by the driving blade, and means to move the anvil between a fastener supporting position and a retracted position to permit feeding of the fasteners into the nose piece.
 2. A pneumatic fastener driving tool as defined in claim 1 including a safety probe carried by the nose piece for controlling the actuation of the trigger mechanism, the anvil connected to the safety probe and being moveable between a fastener supporting position and a retracted position to permit feeding of the fasteners into the nose piece in response to engagement and disengagement of the safety probe with the work surface.
 3. A pneumatic fastener driving tool comprising; an air pressure source, a power head connected to said air pressure source, a piston in said power head adapted to be driven by compressed air from said air pressure source, valving in the power head for controlling the introduction of the compressed air to the piston, trigger mechanism associated with said valving, a nose piece connected to said power head and including means for receiving a drivable fastener, a driving blade connected to said piston and adapted to be driven through said power head into the nose piece to there engage a fastener for driving the fastener into a work surface, a magazine connected to the nose piece including feeding mechanism for feeding fasteners into the nose piece, an anvil carried by the nose piece and aligned with the fastener in the magazine which immediately follows the one contained in the nose piece, a safety probe carried by the nose piece controlling the actuation of the trigger mechanism, a bracket connecting the anvil to the safety probe to move the anvil between a fastener supporting position and a retracted position to permit feeding of the fasteners into the nose piece in response to engagement and disengagement of the safety probe with the work surface, said anvil being removably connected to the bracket whereby the anvil can be interchanged with other anvils to accommodate different lengths of fasteners. 